I still think brad maddox is the leader of the shield
i know evryone says that cena will never turn heel but its true vince will never (in the near future) allow one of his main faces and the face of his company who generates millions through merchandise sales to small kids to turn heel and loose those sales !
that being said lets look at the facts
1)brad maddox attacked ryback and then cuts a promo about injustice
2)all members of the shield are from nxt and so was brad maddox
3)everytime paul heyman talks to brad maddox somethings happens and the way heyman tries to distance himself from brad maddox may be because heyman knows that maddox is behind the shield and that he doesnt want to be seen associated with them but on last weeks raw i think heyman ask's maddox again to get the shield to attack the rock in the rumble
the main clue is that both brad maddox and the shield stand for injustice so my money would be on maddox eventually being revealed as the leader ....